Modelling the influence of cracking and healing on modal properties of concrete beams

Concrete structures are commonly cracked when in service. To overcome issues arising from cracking, self-healing concrete is being developed. Together with the development of the material, techniques to verify and quantify self-healing are being developed. A number of destructive techniques have been used in the past. It would be beneficial to use non-destructive testing for continuous monitoring of self-healing. It is well known that cracking causes changes in natural frequencies of structural elements. A change in natural frequencies can be, therefore, used as an indication of damage. Consequently, the recovery of natural frequencies can be used as an indication of healing. In this work, a model which enables calculation of mode shapes and natural frequencies is presented. First, it is shown that the proposed 2D model can reasonably mimic modal behavior of thin structures under different boundary conditions [6]. It is then used to assess the influence of cracking and healing on the change of modal properties of concrete beams. Finally, based on the modelling results, conclusions are drawn.